Antibiotic resistance results from bacteria's uncanny ability to morph and adapt, outwitting pharmaceuticals that are supposed to kill them. But exactly how the bacteria acquire and spread that resistance inside individuals carrying them is not well-established for most bacterial organisms. Now, University at Buffalo microbiologists studying bacterial colonization in mice have discovered how the very rapid and efficient spread of antibiotic resistance works in the respiratory pathogen, Streptococcus pneumoniae (also known as the pneumococcus). The UB team found that resistance stems from the transfer of DNA between bacterial strains in biofilms in the nasopharynx, the area just behind the nose.